1. Field of the Invention
The present invention relates to an image forming apparatus and a cartridge which can be mounted in the image forming apparatus.
2. Description of Related Art
A tandem type image forming apparatus has photoconductors, exposure units, developing units, and transfer units, each corresponding to the number of colors (for example, four colors of magenta, cyan, yellow and black). When the photoconductors, the developing units, and the like are replaced and maintained, or when a jam process is performed, it is necessary to remove the photoconductors, the developing units, and the like from an image forming apparatus body.
An image forming apparatus disclosed in Japanese unexamined patent application publication No. 2001-272899 has processing units constituted corresponding to the number of colors and guides for sliding the process units. Each processing unit has photoconductors, a developing unit, and the like. Each processing unit is slidable horizontally along each guide to be quickly attached to and detached from the image forming apparatus body. At the time of maintenance or replacement, only a necessary processing unit which requires maintenance or replacement may be removed.
However, in the image forming apparatus, in case of performing a maintenance of a member located inside the processing unit when, for example, a conveying belt for conveying a paper sheet is replaced or a jam process is performed, it is necessary to draw out the processing unit entirely from the image forming apparatus body. Accordingly, the efficiency of the maintenance is low.
Further, the guide is formed to move the processing unit in parallel with the front surface of the conveying belt, etc. Accordingly, in some cases, the photoconductor or the like provided in the processing unit and the conveying belt or the like are slidably contacted with each other to be damaged.
To solve such a problem, an image forming apparatus disclosed in Japanese unexamined patent application publication No. 2003-015378 has a cartridge which is configured of integrated processing units provided corresponding to the number of colors, and is attachable and detachable. According to this image forming apparatus, all of the processing units can be drawn out at a time by drawing the cartridge from the image forming apparatus body. Therefore, its maintenance efficiency is better as compared with the image forming apparatus disclosed in Japanese unexamined patent application publication No. 2001-272899.
Furthermore, after the cartridge is once moved in a direction separating the photoconductor from the belt, the cartridge is drawn out from the image forming apparatus body by sliding the cartridge horizontally with the body. Accordingly, it can prevent the photoconductor and the conveying belt or the like from being brought into slidable contact with each other.
However, since in the image forming apparatus disclosed in Japanese unexamined patent application publication No. 2003-015378, a guiding mechanism, or the like for guiding the cartridge is complicated, its cost is high. Further, since an operation is necessary to separate the photoconductor from the belt before the cartridge is drawn out, its operability or maintenance efficiency is not good.